def getFrame(self):
''' Get the next frame from the buffer
:returns: The frame data or ''
'''
raise NotImplementedException(
"Method not implemented by derived class")
def setValues(self, address, values):
''' Returns the requested values from the datastore
:param address: The starting address
:param values: The values to store
'''
raise NotImplementedException("Datastore Value Retrieve")
def send(self, message):
''' Send a request (string) to the network
:param message: The unencoded modbus response
'''
raise NotImplementedException(
"Method not implemented by derived class")
def decode(self, data):
''' Decodes data part of the message.
:param data: is a string object
:raises: A not implemented exception
'''
raise NotImplementedException()
def connect(self):
''' Connect to the modbus remote host
:returns: True if connection succeeded, False otherwise
'''
raise NotImplementedException(
"Method not implemented by derived class")
def checkFrame(self):
''' Check and decode the next frame
:returns: True if we successful, False otherwise
'''
raise NotImplementedException(
"Method not implemented by derived class")
def lookupPduClass(self, function_code):
''' Use `function_code` to determine the class of the PDU.
:param function_code: The function code specified in a frame.
:returns: The class of the PDU that has a matching `function_code`.
'''
raise NotImplementedException(
"Method not implemented by derived class")
def _recv(self, size):
''' Reads data from the underlying descriptor
:param size: The number of bytes to read
:return: The bytes read
'''
raise NotImplementedException(
"Method not implemented by derived class")
def getValues(self, address, count=1):
''' Returns the requested values from the datastore
:param address: The starting address
:param count: The number of values to retrieve
:returns: The requested values from a:a+c
'''
raise NotImplementedException("Datastore Value Retrieve")
def advanceFrame(self):
''' Skip over the current framed message
This allows us to skip over the current message after we have processed
it or determined that it contains an error. It also has to reset the
current frame header handle
'''
raise NotImplementedException(
"Method not implemented by derived class")
def decode(self, message):
''' Wrapper to decode a given packet
:param message: The raw modbus request packet
:return: The decoded modbus message or None if error
'''
raise NotImplementedException(
"Method not implemented by derived class")
def _send(self, request):
''' Sends data on the underlying socket
:param request: The encoded request to send
:return: The number of bytes written
'''
raise NotImplementedException(
"Method not implemented by derived class")
def setValues(self, fx, address, values):
''' Sets the datastore with the supplied values
:param fx: The function we are working with
:param address: The starting address
:param values: The new values to be set
'''
raise NotImplementedException("set context values")
def validate(self, address, count=1):
''' Checks to see if the request is in range
:param address: The starting address
:param count: The number of values to test for
:returns: True if the request in within range, False otherwise
'''
raise NotImplementedException("Datastore Address Check")
def validate(self, fx, address, count=1):
''' Validates the request to make sure it is in range
:param fx: The function we are working with
:param address: The starting address
:param count: The number of values to test
:returns: True if the request in within range, False otherwise
'''
raise NotImplementedException("validate context values")
def build(self):
''' Return the payload buffer as a list
This list is two bytes per element and can
thus be treated as a list of registers.
:returns: The payload buffer as a list
'''
raise NotImplementedException("set context values")
def getValues(self, fx, address, count=1):
''' Validates the request to make sure it is in range
:param fx: The function we are working with
:param address: The starting address
:param count: The number of values to retrieve
:returns: The requested values from a:a+c
'''
raise NotImplementedException("get context values")
def populateResult(self, result):
''' Populates the modbus result with current frame header
We basically copy the data back over from the current header
to the result header. This may not be needed for serial messages.
:param result: The response packet
'''
raise NotImplementedException(
"Method not implemented by derived class")
def addToFrame(self, message):
''' Add the next message to the frame buffer
This should be used before the decoding while loop to add the received
data to the buffer handle.
:param message: The most recent packet
'''
raise NotImplementedException(
"Method not implemented by derived class")
def isFrameReady(self):
''' Check if we should continue decode logic
This is meant to be used in a while loop in the decoding phase to let
the decoder know that there is still data in the buffer.
:returns: True if ready, False otherwise
'''
raise NotImplementedException(
"Method not implemented by derived class")
def buildPacket(self, message):
''' Creates a ready to send modbus packet
The raw packet is built off of a fully populated modbus
request / response message.
:param message: The request/response to send
:returns: The built packet
'''
raise NotImplementedException(
"Method not implemented by derived class")
def calculateRtuFrameSize(cls, buffer):
''' Calculates the size of a PDU.
:param buffer: A buffer containing the data that have been received.
:returns: The number of bytes in the PDU.
'''
if hasattr(cls, '_rtu_frame_size'):
return cls._rtu_frame_size
elif hasattr(cls, '_rtu_byte_count_pos'):
return rtuFrameSize(buffer, cls._rtu_byte_count_pos)
else:
raise NotImplementedException(
"Cannot determine RTU frame size for %s" % cls.__name__)
def processIncomingPacket(self, data, callback):
''' The new packet processing pattern
This takes in a new request packet, adds it to the current
packet stream, and performs framing on it. That is, checks
for complete messages, and once found, will process all that
exist. This handles the case when we read N + 1 or 1 / N
messages at a time instead of 1.
The processed and decoded messages are pushed to the callback
function to process and send.
:param data: The new packet data
:param callback: The function to send results to
'''
raise NotImplementedException(
"Method not implemented by derived class")
def encode(self):
''' Encodes the status bits to an event message
:returns: The encoded event message
'''
raise NotImplementedException()
def decode(self, event):
''' Decodes the event message to its status bits
:param event: The event to decode
'''
raise NotImplementedException()
def encode(self):
''' Encodes the message
:raises: A not implemented exception
'''
raise NotImplementedException()
def handle(self):
''' Callback when we receive any data
'''
raise NotImplementedException(
"Method not implemented by derived class")
def execute(self, *args):
''' Base function to raise if not implemented '''
raise NotImplementedException(
"Diagnostic Message Has No Execute Method")
def reset(self):
''' Resets all the datastores to their default values '''
raise NotImplementedException()